HP-48GX <==> Macintosh: help, please!


I would like to connect my HP-48GX to my Macintosh (blue & white G3, OS 10.2.6); would some kind and knowledgeable person, or persons, please e-mail me some information to assist me in this endeavour? I am not familiar with either the software, or the hardware involved. When I search the HP site, there is a choice of more than one cable that appears to be designed for this application, but there is no accompanying information about which model(s) of Mac they are intended for, or with which OS the software is intended to function. In short, I am no wiser for having visited the HP site.

As all readers will know, there is also the problem of obtaining the part(s), if they are HP, so I would also appreciate some pointers on where to obtain what it is that I need.

I know I'm asking a lot, but HP customer support referred me here, so I am hoping that the answers will be found here.

Please e-mail: slockyer@cox.net

Many thanks in advance, Simon


I have an HP-48SX with a similar (not same) serial cable and I used to use it with my older Macintosh computers. Let me offer what I know.

The calculator to Mac cables used the Apple serial round connector. The calculator to PC cable used the 9-pin D shell serial style connector for PCs. This connector is not compatible with your Blue and White (or any other recent Macintosh) which use USB ports and not serial ports.

A company (name is out of head for the moment) makes serial to USB converters. I have used the original model of this adapter to mate my calculator, printer, and Newton to the computer (years ago now). The later versions of the USB serial adapter offered both Apple style and PC style connectors.

That may help you solve the physical connection problem. Now comes the software problem. You need a program to talk to a serial port. In the old days, Mac OS 7, 8, and 9, this was done with a modem program like KERMIT or the terminal application in the older AppleWorks program.

The HP-48SX used KERMIT file transfer, the GX may be similar.

The last time I did any of this stuff was under OS 9 on an iMac long before even the beta release of OS X!

I may look for my old serial to USB adapter and try it out, but I think the version I have is no longer supported and I haven't even thought about how it might work under OS X (I too used 10.2.6 now).

If I have an answer, I will add a new post. Contact me if you wish.

Good luck.


I found the USB to Serial converter!
It is made by a company called Keyspan.
The model I have is the USA-28 and I know it was replaced by one called the USA-28A and probably others.
Look for www.keyspan.com (I haven't bothered yet).

I also dug up my HP-48SX serial cable and the software disks, but the HP disk is the old 800K flavor and my USB floppy disk drive only reads the 1.44MB flavor disks. I will be taking the disks to work and converting them.
I am going to see if the program it came with the cable will run under Classic (now I am curious). Then I will see if the old Keyspan will work with OS X at all.

This is something I have been wondering about myself. I have an old Macintosh in the basement that the software and the cable will work with, but that is no use to you nor is it of interest to me.


I can confirm that the 48S series and 48G series use the same Kermit protocol and the same cable. The 48G series also includes a built-in XModem protocol that the 48S series doesn't have. I may be able to help on the various I/O settings on the calculator, but I've never had a Mac, so I can't help you at that end of the connection


There was a post last week or so on using the HP48 calculators with a Mac, I have been playing with this for a week now.

You need a KeySpan USB to serial adapter as well as the cable for the calculator. I have a KeySpan USA-28. The latest software from them installs and behaves as they describe. In OS X, the two ports appear in the /dev directory as soon as the unit is plugged in.

If you have the KeySpan USB adapter and the latest software from them, you may be able to use AppleWorks 5 for OS 9 to link to a HP48G series. AppleWorks 5 (but not 6) had a communications module with XModem, but not Kermit. I have an HP48SX and could not test this.

I have searched for OS X applications that support modem operation and have two candidates.

One is the original C-Kermit program, but this is a terminal (no GUI) application and it is anything but user friendly, just installing it from the download takes several not so obvious commands.

Not only that, but the command to connect to the port is not accepting any of the device names I have tried. I have a trouble report open with them asking about this.

There is an alternative called PowerTerminal, and I trying to get the demo version to download, but it times out each time I try. You can find it with Version Tracker by searching for "terminal emulation".

If anyone has this or tries it, let us know. I will be trying again.

Once I get something to work, I'll be back with a post.

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